dmaengine: imx-sdma: fix up param for the last BD in sdma_prep_slave_sg()

As per the reference manual, bit "L" should be set while bit "C"
should be cleared for the last buffer descriptor in the non-cyclic
chain, so that sdma can stop trying to find the next BD and end
the transfer.

In case of sdma_prep_slave_sg(), BD_LAST needs to be set and BD_CONT
be cleared for the last BD.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index cf93d1737f1e99766dd7029d33eb5d2515923a96..4535f98b35537299eee84ca5b84083f2fa128422 100644 (file)
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -931,8 +931,11 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
 
                param = BD_DONE | BD_EXTD | BD_CONT;
 
-               if (i + 1 == sg_len)
+               if (i + 1 == sg_len) {
                        param |= BD_INTR;
+                       param |= BD_LAST;
+                       param &= ~BD_CONT;
+               }
 
                dev_dbg(sdma->dev, "entry %d: count: %d dma: 0x%08x %s%s\n",
                                i, count, sg->dma_address,